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-   Supercharger Discussion (https://www.miataturbo.net/supercharger-discussion-38/)
-   -   EO2K contemplates the universe, his rotrex, and why they both fail (https://www.miataturbo.net/supercharger-discussion-38/eo2k-contemplates-universe-his-rotrex-why-they-both-fail-62346/)

phenixmt 06-08-2012 04:41 AM


Originally Posted by EO2K (Post 884820)

Reading the "MAT correction" thread and that might explain what is making my ARFs do goofy crap while playing with VEAL. It keeps adding, then removing, then adding, then removing... I need to see if I can create a MAT Correction gauge in TS to watch, or maybe find out if VEAL ignores MAT Correction...

Do you still have problem with MAT correction? VEAL is behaving well now?

EO2K 06-08-2012 10:55 AM

Kinda sorta... its not adding and removing as much fuel now, but its still doing it. I added EGO and a Accel Enrichment gauges to TS last night before I drove home so I could keep an eye on them, EAE is set to off. My AE looks like it was configured (by default) to operate between 2500 & 5000 RPM, but I saw no evidence it was actually doing anything, if the gauge is to be believed. I changed the setpoints to 7200 & 7250 or something so I don't expect to hear anything from it any time soon :giggle:

As far as I can tell, EGO, AE and EAE are all turned off. As soon as I get GAIR under control things should stabilize a bit more. I'm still trying to read up on this and haven't had a lot of time to play with it. Everything in time I guess.

For some reason I had VEAL set to not touch any of my cells under 1000rpm and I was idling SUPER FAT even after WUE turned off. It pulled a ton of fuel out and its now significantly closer to my 14.7 target and the RPM fluctuations are minimal at best, but I'm still getting an unexplained AFR swing. Bah!

EO2K 06-18-2012 04:12 PM

Rotrex Install Instructions
 
6 Attachment(s)
Uploading here because KW has pulled the PDFs off their webserver, and I'm ALL PRO at loosing this kind of stuff. Maybe someone else can use it some day.

Arny 06-18-2012 04:16 PM

Thank you ;)
I will mount my Rotrex in a few weeks and I was looking for the belt tension bulletin.

EO2K 06-18-2012 04:34 PM

Hi Arny! :wavey:
Glad you could use it! You should make an intro thread here on MT and hang out with the "cool kids" :cool:

There is actually a bit of modification you can do to get more tension on the belt, Kraftwerks had to do this to my backing plate to finally get my belts to stay-put. I'll get some pics next time I have the Rotrex out. Depending on how yours turns out, you may not need it.

Arny 06-18-2012 04:47 PM

2 Attachment(s)
The belt tension and the choice of the right belt size is worst part of the mounting for me.

Moreover, I have seen the shape of your pulley and mine is really different. It's a 75mm and the edge of the pulley is flat as you can see here:

https://www.miataturbo.net/attachmen...ine=1340052446

Scooter25 06-18-2012 05:11 PM

Your pulley looks like the actual Rotrex pulley vs. The KW pulley. Does it have 1 bolt or 6?

Arny 06-18-2012 05:19 PM

1 Attachment(s)
Good question, I think it's the same as my other pulley which you can see below :

https://www.miataturbo.net/attachmen...ine=1340054341

EO2K 06-18-2012 05:22 PM

IIRC that's a URD 8 rib Rotrex pulley. I believe a couple guys struck out on their own and bought smaller pulleys from UnderDog Racing when Kraftwerks wouldn't release upgrades. Urdusa.com does a rotrex kit for Toyota applications, but the pulleys are genuine Rotrex units.

The URD site is down at the moment but this *should* be the link for the page with the pulleys: http://www.urdusa.com/Forced-Inducti...duct_info.html

Edit: URD is back up, changed the URL

Scooter25 06-18-2012 05:23 PM

Looks like 1 large bolt in the middle.

Arny 06-18-2012 05:33 PM

Yes, thank you for the information.
I hope I won't have problems with the belt and the pulley.

EO2K 06-18-2012 05:51 PM

1 Attachment(s)
looks about right:
https://www.miataturbo.net/attachmen...ine=1340056263

I think Falcon may be running one of these on his C30-94 powered 1.6?

Arny 06-18-2012 05:55 PM

It's seems to be those pulley. I have 2 size:70 and 75mm.
I will begin with the 75mm, with a Megasquirt, A/W intercooler, LC1 wideband, Rx8 450cc injectors, I think it will be enough for my stock internals.

Scooter25 06-18-2012 06:11 PM

My 70 is one of them.

Arny 06-18-2012 06:16 PM

And you don't have problem with the pulley or with the auto tensionner?
No tips or special thing to do/know during the install? ;)

EO2K 06-18-2012 06:25 PM

Watch your redlines there Arny...

If I've done the math correctly X,XXX (rpm engine) * 135 (mm crank pulley) / XX (mm rotrex pulley) * 9.49 (rotrex internal ratio) = XXX,XXX rotrex shaft rpm.

Shaft redline on the C30-94 is 100,000rpm whereas the rest of the C30 family is 120,000rpm (this includes our C30-74) and from waht I've been told, these things do NOT like to be overspun.

7200 x 135/88 x 9.49 = 104,366 (86.97%) this is how my kit was delivered
7200 x 135/80 x 9.49 = 115,303 (96.08%) this is the smallest pulley KW would sell me
7200 x 135/75 x 9.49 = 122,990 (102.49%)
7200 x 135/70 x 9.49 = 131,775 (109.81%)

75mm Rotrex pulley & a lower 7,000rpm engine redline is as close as you can get without overspeeding the C30-74, drops you right at 119,574 shaft RPM.

I've been thinking about 80mm @ 7,500rpm (120,107rpm) best of all worlds?

Alternately, I could raise engine rpm to 8,000 with an 88mm pulley and get 116,468 RPM out of the Rotrex, but now you are talking about another $1,000 worth of Supertech hardware in a built head to support that kind of RPM :giggle:

Scooter: Were you running a lower redline with that 70mm? Did you see significantly more heat with more RPM?

Arny 06-18-2012 06:35 PM

Here is my calculation:
7000 (engine) * 135/75 * 9.49 => 119,574 rpm

I will have to put the engine redline at 7000 with the Megasquirt.

Previous owner recorded 224 whp at 10 psi but with larger injectors (550cc).

I have a VVT engine so high compression. (but no VVT tuner for the moment).
I hope it will be ok for the stock internals with this setup.

EO2K 06-18-2012 06:50 PM

Sounds good, just wanted to throw that out there. I was thinking about the 75 & 7,000 combo if Scooter was going to sell me his 75mm pulley, but I'll probably just be a wuss and go 80mm so I won't have to worry about missed shifts or anything :loser:

Arny 06-18-2012 06:53 PM

Thank you for all the advices. I will keep you updated in the following weeks. ;)

Mobius 06-18-2012 09:07 PM

I am planning on the 80mm pulley as well. I am not replacing my stock ecu anytime soon, and have hit the 7200 fuel cut several times at autocross.

Although if I go ms3x I can set fuel cut to 7000 and go with the 75mm. Or just go with the 75mm anyway ... spend very little time at 7k ... hmm.

Edit:

EO2k have you flogged your car yet? As in track days? I did 2 track days, then an autocross, then the 3rd track day Thursday 6/14. After the 2nd session of that day I discovered my belt had managed to invert itself over the crank pulley. Car was still running flawlessly but the belt was down to half width :O. I had set my belt tension to just enough to keep the autotensioner from rattling under acceleration, which on my car was about 4-6mm. This is apparently not tight enough for "race" usage and I will be tightening the new belt further. Also I will ask bellwilliam what tension preload he ran his at.

Being the baus that I am, I of course had a spare belt, and so suffered no inconvenience. But still. It's embarassing when the gentlemen next to you in the paddock with the supercharged Elise asks to check out your ride, and then says "Hey, is your belt supposed to look like that?"


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